Radio Shows | Circadian Rhythms and Jet Lag (contributing author - Sam Strauss, M.D.; NASA JSC) | mp3 … wma … wav

Today, we'll talk about circadian rhythms and jet lag.

Through modern jet travel the world has gotten a lot smaller! This year about a billion people will fly and in two decades that number's expected to double.

But air travel has its challenges, especially long flights that take people across multiple time zones. For example Taiwan is thirteen hours ahead... which means we're off to work as people there are heading to bed. That'd be a tough transition if you're planning a trip.

So why does this happen? The answer lies in biological functions that follow regular daily rhythms or circadian rhythms. They regulate physiological and psychological functions such as the sleep cycle, blood pressure and pulse rate, and body temperature, among others.

When you cross two or more time zones, that's all disrupted and what we suffer is jet lag. The symptoms include mood swings, fatigue and lack of concentration and trouble sleeping at night.

Older people are more susceptible to the symptoms as are people under a lot of stress. And it's worse if you're going eastbound.

There are exceptions, Dave, like day travel which is easier to adjust to and so is north-south travel which doesn't take you across time zones. Also note that jet lag symptoms decline by about 50 per cent a day. It takes roughly one day to adjust for every time zone you cross.

There are things you can do to reduce the symptoms. For shorter trips, stick with your home schedule. And for longer trips try to immediately get on local time.

At your destination, sleep in a dark room, exercise, and eat rapidly absorbed carbohydrates before bed. Plus -medications like melatonin can help because it has sleep inducing effects. Of course you should consult your doctor first.